Turbojet power plant with controllable primary and secondary outlets



Juhe 6, 1950 1' LINDIHAGEN ETAL 2,510,506

TURBO-JET POVER PLANT WITH CONTROLLABLE PRIMARY AND SECONDARY OUTLETS Filed July 14, 1945 7 I z INVEZTORS W/M/ZM M4 Patented June 6, 1950 TROLLABLE' PRIMARY ARY OUTLETS AND SECOND:

Teodor Immanuel Lindhagen, Stockholm, and Gustav Karl William I ioestad, Lidingo, Sweden, assignors, by mesne ents, to Jarvis 0.

Marble, New York, N. Y., Leslie M. Merrill, Westfield, N. J., and Percy H. Batten, Racine,

Wis., as trustees Application July 14, 1945, Serial No. 605,008

Sweden July 15, 1944 1 r This invention relates to airplanes propelled entirely or in part b reactive or Jet propulsion.

Airplanes built for high speed 1 flight have a small liftin surface, so that the landing speed becomes so great as to require long landing strips, if the plane is not braked before landing or on its way over the landing strip. Various means, such as flaps and air brakes, have been used to effect the braking in question. Furthermore, it has been suggested to equip airplanes with a controllable outlet for gases escaping from the driv- 1 Claim. (Cl. 60-35.6)

ing machinery thereof, said outlet being directed forwardly in the direction of movement of the plane while being arranged to have the gases flowing therethrough, when the speed of the plane is to be reduced. The object of this invention is to provide an arrangement of this kind which is capable, inter alia, of effectively reducing the speed of the plane before the landing or during the same, and which in spite of this does not have an interfering effect on the propulsion. This is obtained substantially by the fact that the outlet is constituted by flaps adapted to be withdrawn into the fuselage.

According to the invention, a considerable reduction of the speed is obtained before landing. The braking of the plane takes place still more rapidly, after the plane has touched ground, by reason of the fact that the braking force from the gas streamincreases with a reduced speed of the plane. If an airplane is driven at a speed of 250 metres per second with a reaction motor 50 dimensioned that kilograms of air are blown out per second at a relative velocity with'respect to that of the airplane of 750 metres per second,

a tractive force is obtained equal to 5 (750-250) =500 kilograms corresponding to an output of 5OOX250 75 x 750+-100 =s50 kg.

will be obtained, which power is thus considerably greater than the power propelling the plane. By thus turning the gas stream from the reaction machine forwardly or at an angle to the flying =about 1,700 H. P.

direction of the plane, it will be possible, particularly when such a motor operates at full power, to create a very great braking power, without the propelling properties of the airplane in normal operation being impaired thereby.

The invention will be described more in detail in the following with reference to an embodiment disclosed by way of example in the accompanying diagrammatic drawing, other features characteristic of the invention being then also pointed out.

Fig. 1 shows a portion of an airplane provided with a braking device constructed in accordance with the invention, this figure being a longitudinal section; and

Figs. 2 and 3 are sections on lines IIII and III-III, respectively, in Fig. 1.

In the drawing, I0 designates the rear portion of the fuselage of an airplane and a body inserted therein. At the rear, the fuselage III has an outlet openin l2 for the exhaust gases from the driving machinery of the airplane, such machinery being formed, entirely or in part, for

reactive operation. A portion of this driving machinery, that is to say a gas turbine H, is shown in Fig. 1. The gaseous driving medium still has a certain pressure above atmospheric on having passed through the turbine, when said drivin medium enters the chamber l6 at the rear end of the fuselage. may be formed in any suitable manner known per se and has no bearing on the present invention, it will not be described in detail herein.

Inserted into the outlet portion of the chamber I6 is a streamline-shaped valve body [8, which in the normal forward flight of the plane takes a position corresponding to that indicated by chaindotted lines in Fig. l, the exhaust gases flowing at a high velocity through the reaction nozzle 20 formed between the shell l0 and the valve body. The valve-body I8 is displaceable to control the area of the outlet 20, which is entirely closed when-the valve body takes the position shown by full lines in Fig. 1. The valve body l8 has an internal cylindrical portion 22 sliding on and guided by a cylinder 24 rigidly arranged at the center of the fuselage. A piston 28 is slidable within a chamber 26 in said cylinder, and is connected to a rod 30 extending through the rear end wall of the chamber and-rigidly connected with the valve body I8. A pressure fluid, such as oil, is introduced into the chamber 26 on one side of the piston 28 through a conduit 32, and is supplied to the other side of said piston through a pipe 34, which opens into the chamber 26 through Inasmuch as the driving machinery radial holes a in the rod :0. The pipe :4 is sneably fitted into a pipe 4|! secured in the cylinder 24 or in the partition 38 thereof.

The cylinder 24 is,.cnnected by means of a funnel-shaped sleeve 42 to the frame of the turbine I4. The parts 24, 4 2 are surrounded by a sleeve 44 likewise connected to the turbine frame,

said sleeve 44 being retained in position byradially disposed pipes 48 and abutting against the cylinder 24 with the aid of a flange 48, so that this cylinder will be safely braced. Cooling air is taken in through the pipes 45, said air. flowing both ways in" the intermediate space between the parts 24, 42 and 44. Provided on one side of the sleeve 44 are outlets 50 for cooling air flowing piston chamber 26, and continues through the valve body l8xand through openings into the atmosphere.

Provided in the fuselage I0 in front of the outlet l2 are openings having flaps 56 arranged therein. Thus four of such flaps may be 'disg5 tributed about the circumference of the fuselage. The flaps 55' are pivotally' mounted in the fuselags it, as at 58, at the rear edge of the openings, and are U-shaped in section, at right angles to the longitudinal direction of the airplane.

When taking their open position, as shown in the figures, they form outlet openings against or at an angle to the flying direction of. the airplane, and their lateral walls so prevent the gases flowme out through the same from expanding sideways. These outlets are arranged so that the escaping gas slips from the wall of the fuselage, and so that the gas jets do not blow against the side rudder of the airplane or against the stabilizer or the wings thereof. In their closed position, the flaps 56 have the outside thereof lying flush with the fuselage, that is to say in a manner such as to offer a minimum of resistance to the air. The flaps 56 are pivotally mounted to a link 64, as at 62, said link being connected to Number the rod 66 of apiston 58 running in a cylinder 10. The two sides of the latter are supplied with the pressure fluid, such as oil, through conduits I2, 14. The flaps 56 may open either outwardly,

according to the upper portion of Fig. 1, or inwardly according to the lower portion of said figure. 5

When the plane is braked, pressure oil is introduced through the conduit 32, so that the valve body i8 is caused to close the normal gas outlet l2. At the same time, pressure oil is introduced through the inlets 14 into the cylinders 10, whereby the flaps 56 are caused to open. The exhaust gases from the driving machinery are then compelled to escape through the outlet openings formed by the flaps, so that an output to brake the forward movement of the plane is obtained.

Obviously, the invention is not restricted to the embodiment disclosed. but may be varieddn the widest sense within the scope of the appended claim.

What is claimed:

In an aircraft havinga power plant including a gas turbine discharging gases to the ambient atmosphere, means providing an annular passtage for flow of gas from said turbine to a pri- *mary outlet directed rearwardly of the aircraft,

said means comprising an outer casing and an inner tubular structure concentric with and spaced from said outer casing, a hollow valve body 'slidably carried by said .tubular structure, fluid pressure actuated means for moving said 1 valve body between a flrst position coacting with said outer casing to close said primary outlet 1 and a second position coacting with said outercasing to open said primary outlet into annular form, means for cooling said tubular structure and said valve body comprising'passages for ad- Y mitting air from the ambient atmosphere to the interior of said tubular structure and discharge openings in said valve body for egress of cooling air to the ambient atmosphere, a'plurality of secondary outlets in said outer casing for placing said annular gas passage in communication with the atmosphere, valve means for controlling each of said secondary outlets, said valve means comprising valve members arranged to direct gases from said gas channel substantially forwardly of the aircraft when said secondary outlets are opened and fluid pressure actuated means for moving said valve members to open or close said secondary outlets.

' ,4 r REFERENCES CITED .The following references are of record in the file of this patent:

UNITED STATES fia'rrm'rs Name Date 340,237 Nagel et a1. Apr. 20, 1886 1,611,353 Lepinte Dec, 21, 1926 1,669,495 'Sloan May 15, 1928 2,280,835 Lysholm Apr. 28, 1942 2,383,385 Heintz Aug. 21, 1945 2,395,435 Thompson et a1. Feb. 26, 1946 2,402,363 Bradbury June 18, 1946 FOREIGN PATENTS Number Country Date 4,322 Great Britain Nov. 8, 1876 OTHER REFERENCES "Spear Shaped -Weather Rocket," by C. P. Lent,

oo in Astronautics, March 1944, pages 11-13. 

